Re: Question on special class description

hmm, I think this case is a different one: it requires to characterise  
those humans who love all their children...i.e., you look at a person,  
check the image of 'loves' and 'hasChild' and, depending on the  
outcome, make them an instance of 'GoodParent'...

I guess that DL safe rules would be one way out, at least on the  
individual level.

Another work-around would be to add a sub-property,  
hasChildAndLovesIt, of hasChild and loves, and see how far you get  
with this, which strongly depends on your modelling and on the other  
stuff you say....e.g., if you never *say* that somebody loves their  
children, we can always assume that the elements that somebody loves  
are disjoint from their children...

Cheers, Uli

On 1 Mar 2010, at 14:21, Alan Rector wrote:

> Isn't this a variant of the "all-all" question - Uli's "Cat-lovers"  
> problem
>
> - e.g.
>
> "All people with driving licenses are authorised to drive all cars"
>
> It is just turning it into an equivalence class statment:
>
> "All people authorised to drive all cars" equivalent to "People with  
> driving licenses"
>
> replace "authorised to drive all cars" with "loves all children"
>
> and you are close.
>
> That it has to be his child complicates it a bit, but it is part of  
> the same family of problems,
> which we know have no simple solution in OWL DL.
> We know this can only be done with awkward constructions involving  
> individuals.
>
> Alan
>
> On 23 Feb 2010, at 19:10, Thomas Schneider wrote:
>
>> Hi Lennart,
>>
>> I can only see two ways, and they lead out of OWL-DL, but perhaps  
>> someone else here has a better idea?
>>
>> (1) If you use Boolean operators on roles, you can define a new  
>> role hasChildButDoesNotLoveIt to be "hasChild and not loves". You  
>> can then define the desired class as GoodParent =  
>> hasChildButDoesNotLoveIt only Nothing.
>>
>> (2) If you define a new property p to be a superproperty of the  
>> chain "hasChild o inv(loves)", then you can define a GoodParent to  
>> be equivalent to not p some Self. Unfortunately, only simple object  
>> property expressions are allowed in hasSelf restrictions and p is  
>> composite due to the first statement.
>>
>> I suppose this doesn't really help ... :-S
>>
>> Cheers
>>
>> Thomas
>>
>> On 23 Feb 2010, at 15:35, Lennart Bierkandt wrote:
>>
>>> Hello,
>>>
>>> I am developing an ontology for a linguistic typological database,  
>>> where I need to describe a class of the form:
>>> { x | ∀y( r1(x,y) -> r2(x,y) ) }
>>> As explaining the real use of this would be to complicated,  
>>> imagine a class denoting e.g. "people who love (r2: loves) all  
>>> their children (r1: hasChild) (or haven't any)".
>>>
>>> In prose it doesn't seem to be too complex, but I didn't find a  
>>> way to do it..
>>> CAN this be expressed in OWL-DL? and if, how? (and if not, in OWL- 
>>> FULL?)
>>>
>>> Kind regards,
>>> Lennart Bierkandt
>>>
>>>
>>>
>>
>> + 
>> ----------------------------------------------------------------------+
>> |  Dr Thomas Schneider                    schneider (at)  
>> cs.man.ac.uk  |
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>>
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>>
>>
>
> -----------------------
> Alan Rector
> Professor of Medical Informatics
> School of Computer Science
> University of Manchester
> Manchester M13 9PL, UK
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Received on Monday, 1 March 2010 15:07:01 UTC